[linux-2.6-block.git] / drivers / rtc / rtc-pcf8563.c

/*
 * An I2C driver for the Philips PCF8563 RTC
 * Copyright 2005-06 Tower Technologies
 *
 * Author: Alessandro Zummo <a.zummo@towertech.it>
 * Maintainers: http://www.nslu2-linux.org/
 *
 * based on the other drivers in this same directory.
 *
 * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/i2c.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/slab.h>

#define DRV_VERSION "0.4.3"

#define PCF8563_REG_ST1		0x00 /* status */
#define PCF8563_REG_ST2		0x01

#define PCF8563_REG_SC		0x02 /* datetime */
#define PCF8563_REG_MN		0x03
#define PCF8563_REG_HR		0x04
#define PCF8563_REG_DM		0x05
#define PCF8563_REG_DW		0x06
#define PCF8563_REG_MO		0x07
#define PCF8563_REG_YR		0x08

#define PCF8563_REG_AMN		0x09 /* alarm */
#define PCF8563_REG_AHR		0x0A
#define PCF8563_REG_ADM		0x0B
#define PCF8563_REG_ADW		0x0C

#define PCF8563_REG_CLKO	0x0D /* clock out */
#define PCF8563_REG_TMRC	0x0E /* timer control */
#define PCF8563_REG_TMR		0x0F /* timer */

#define PCF8563_SC_LV		0x80 /* low voltage */
#define PCF8563_MO_C		0x80 /* century */

static struct i2c_driver pcf8563_driver;

struct pcf8563 {
	struct rtc_device *rtc;
	/*
	 * The meaning of MO_C bit varies by the chip type.
	 * From PCF8563 datasheet: this bit is toggled when the years
	 * register overflows from 99 to 00
	 *   0 indicates the century is 20xx
	 *   1 indicates the century is 19xx
	 * From RTC8564 datasheet: this bit indicates change of
	 * century. When the year digit data overflows from 99 to 00,
	 * this bit is set. By presetting it to 0 while still in the
	 * 20th century, it will be set in year 2000, ...
	 * There seems no reliable way to know how the system use this
	 * bit.  So let's do it heuristically, assuming we are live in
	 * 1970...2069.
	 */
	int c_polarity;	/* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
};

/*
 * In the routines that deal directly with the pcf8563 hardware, we use
 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
 */
static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
	unsigned char buf[13] = { PCF8563_REG_ST1 };

	struct i2c_msg msgs[] = {
		{ client->addr, 0, 1, buf },	/* setup read ptr */
		{ client->addr, I2C_M_RD, 13, buf },	/* read status + date */
	};

	/* read registers */
	if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
		dev_err(&client->dev, "%s: read error\n", __func__);
		return -EIO;
	}

	if (buf[PCF8563_REG_SC] & PCF8563_SC_LV)
		dev_info(&client->dev,
			"low voltage detected, date/time is not reliable.\n");

	dev_dbg(&client->dev,
		"%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
		"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
		__func__,
		buf[0], buf[1], buf[2], buf[3],
		buf[4], buf[5], buf[6], buf[7],
		buf[8]);


	tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
	tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
	tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
	tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
	tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
	tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
	tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
	if (tm->tm_year < 70)
		tm->tm_year += 100;	/* assume we are in 1970...2069 */
	/* detect the polarity heuristically. see note above. */
	pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
		(tm->tm_year >= 100) : (tm->tm_year < 100);

	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
		"mday=%d, mon=%d, year=%d, wday=%d\n",
		__func__,
		tm->tm_sec, tm->tm_min, tm->tm_hour,
		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

	/* the clock can give out invalid datetime, but we cannot return
	 * -EINVAL otherwise hwclock will refuse to set the time on bootup.
	 */
	if (rtc_valid_tm(tm) < 0)
		dev_err(&client->dev, "retrieved date/time is not valid.\n");

	return 0;
}

static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
	int i, err;
	unsigned char buf[9];

	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
		"mday=%d, mon=%d, year=%d, wday=%d\n",
		__func__,
		tm->tm_sec, tm->tm_min, tm->tm_hour,
		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

	/* hours, minutes and seconds */
	buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
	buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
	buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);

	buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);

	/* month, 1 - 12 */
	buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);

	/* year and century */
	buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
	if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
		buf[PCF8563_REG_MO] |= PCF8563_MO_C;

	buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;

	/* write register's data */
	for (i = 0; i < 7; i++) {
		unsigned char data[2] = { PCF8563_REG_SC + i,
						buf[PCF8563_REG_SC + i] };

		err = i2c_master_send(client, data, sizeof(data));
		if (err != sizeof(data)) {
			dev_err(&client->dev,
				"%s: err=%d addr=%02x, data=%02x\n",
				__func__, err, data[0], data[1]);
			return -EIO;
		}
	};

	return 0;
}

struct pcf8563_limit
{
	unsigned char reg;
	unsigned char mask;
	unsigned char min;
	unsigned char max;
};

static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	return pcf8563_get_datetime(to_i2c_client(dev), tm);
}

static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	return pcf8563_set_datetime(to_i2c_client(dev), tm);
}

static const struct rtc_class_ops pcf8563_rtc_ops = {
	.read_time	= pcf8563_rtc_read_time,
	.set_time	= pcf8563_rtc_set_time,
};

static int pcf8563_probe(struct i2c_client *client,
				const struct i2c_device_id *id)
{
	struct pcf8563 *pcf8563;

	int err = 0;

	dev_dbg(&client->dev, "%s\n", __func__);

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
		return -ENODEV;

	pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL);
	if (!pcf8563)
		return -ENOMEM;

	dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");

	i2c_set_clientdata(client, pcf8563);

	pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name,
				&client->dev, &pcf8563_rtc_ops, THIS_MODULE);

	if (IS_ERR(pcf8563->rtc)) {
		err = PTR_ERR(pcf8563->rtc);
		goto exit_kfree;
	}

	return 0;

exit_kfree:
	kfree(pcf8563);

	return err;
}

static int pcf8563_remove(struct i2c_client *client)
{
	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);

	if (pcf8563->rtc)
		rtc_device_unregister(pcf8563->rtc);

	kfree(pcf8563);

	return 0;
}

static const struct i2c_device_id pcf8563_id[] = {
	{ "pcf8563", 0 },
	{ "rtc8564", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, pcf8563_id);

static struct i2c_driver pcf8563_driver = {
	.driver		= {
		.name	= "rtc-pcf8563",
	},
	.probe		= pcf8563_probe,
	.remove		= pcf8563_remove,
	.id_table	= pcf8563_id,
};

static int __init pcf8563_init(void)
{
	return i2c_add_driver(&pcf8563_driver);
}

static void __exit pcf8563_exit(void)
{
	i2c_del_driver(&pcf8563_driver);
}

MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);

module_init(pcf8563_init);
module_exit(pcf8563_exit);
Commit	Line	Data
b5a82d62 AZ	1	/*
	2	* An I2C driver for the Philips PCF8563 RTC
	3	* Copyright 2005-06 Tower Technologies
	4	*
	5	* Author: Alessandro Zummo <a.zummo@towertech.it>
	6	* Maintainers: http://www.nslu2-linux.org/
	7	*
	8	* based on the other drivers in this same directory.
	9	*
	10	* http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License version 2 as
	14	* published by the Free Software Foundation.
	15	*/
	16
	17	#include <linux/i2c.h>
	18	#include <linux/bcd.h>
	19	#include <linux/rtc.h>
5a0e3ad6	20	#include <linux/slab.h>
b5a82d62	21
e5fc9cc0	22	#define DRV_VERSION "0.4.3"
b5a82d62 AZ	23
	24	#define PCF8563_REG_ST1 0x00 /* status */
	25	#define PCF8563_REG_ST2 0x01
	26
	27	#define PCF8563_REG_SC 0x02 /* datetime */
	28	#define PCF8563_REG_MN 0x03
	29	#define PCF8563_REG_HR 0x04
	30	#define PCF8563_REG_DM 0x05
	31	#define PCF8563_REG_DW 0x06
	32	#define PCF8563_REG_MO 0x07
	33	#define PCF8563_REG_YR 0x08
	34
	35	#define PCF8563_REG_AMN 0x09 /* alarm */
	36	#define PCF8563_REG_AHR 0x0A
	37	#define PCF8563_REG_ADM 0x0B
	38	#define PCF8563_REG_ADW 0x0C
	39
	40	#define PCF8563_REG_CLKO 0x0D /* clock out */
	41	#define PCF8563_REG_TMRC 0x0E /* timer control */
	42	#define PCF8563_REG_TMR 0x0F /* timer */
	43
	44	#define PCF8563_SC_LV 0x80 /* low voltage */
	45	#define PCF8563_MO_C 0x80 /* century */
	46
e5fc9cc0 AZ	47	static struct i2c_driver pcf8563_driver;
e5fc9cc0 AZ	48
cbb94502	49	struct pcf8563 {
e5fc9cc0	50	struct rtc_device *rtc;
cbb94502 AN	51	/*
	52	* The meaning of MO_C bit varies by the chip type.
	53	* From PCF8563 datasheet: this bit is toggled when the years
	54	* register overflows from 99 to 00
	55	* 0 indicates the century is 20xx
	56	* 1 indicates the century is 19xx
	57	* From RTC8564 datasheet: this bit indicates change of
	58	* century. When the year digit data overflows from 99 to 00,
	59	* this bit is set. By presetting it to 0 while still in the
	60	* 20th century, it will be set in year 2000, ...
	61	* There seems no reliable way to know how the system use this
	62	* bit. So let's do it heuristically, assuming we are live in
	63	* 1970...2069.
	64	*/
	65	int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
	66	};
	67
b5a82d62 AZ	68	/*
	69	* In the routines that deal directly with the pcf8563 hardware, we use
	70	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
	71	*/
	72	static int pcf8563_get_datetime(struct i2c_client client, struct rtc_time tm)
	73	{
e5fc9cc0	74	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
b5a82d62 AZ	75	unsigned char buf[13] = { PCF8563_REG_ST1 };
	76
	77	struct i2c_msg msgs[] = {
	78	{ client->addr, 0, 1, buf }, /* setup read ptr */
	79	{ client->addr, I2C_M_RD, 13, buf }, /* read status + date */
	80	};
	81
	82	/* read registers */
	83	if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
2a4e2b87	84	dev_err(&client->dev, "%s: read error\n", __func__);
b5a82d62 AZ	85	return -EIO;
	86	}
	87
	88	if (buf[PCF8563_REG_SC] & PCF8563_SC_LV)
	89	dev_info(&client->dev,
	90	"low voltage detected, date/time is not reliable.\n");
	91
	92	dev_dbg(&client->dev,
	93	"%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
	94	"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
2a4e2b87	95	__func__,
b5a82d62 AZ	96	buf[0], buf[1], buf[2], buf[3],
	97	buf[4], buf[5], buf[6], buf[7],
	98	buf[8]);
	99
	100
fe20ba70 AB	101	tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
	102	tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
	103	tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
	104	tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
b5a82d62	105	tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
fe20ba70 AB	106	tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
fe20ba70 AB	107	tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
cbb94502 AN	108	if (tm->tm_year < 70)
	109	tm->tm_year += 100; /* assume we are in 1970...2069 */
	110	/* detect the polarity heuristically. see note above. */
	111	pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
	112	(tm->tm_year >= 100) : (tm->tm_year < 100);
b5a82d62 AZ	113
	114	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
	115	"mday=%d, mon=%d, year=%d, wday=%d\n",
2a4e2b87	116	__func__,
b5a82d62 AZ	117	tm->tm_sec, tm->tm_min, tm->tm_hour,
	118	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	119
	120	/* the clock can give out invalid datetime, but we cannot return
	121	* -EINVAL otherwise hwclock will refuse to set the time on bootup.
	122	*/
	123	if (rtc_valid_tm(tm) < 0)
	124	dev_err(&client->dev, "retrieved date/time is not valid.\n");
	125
	126	return 0;
	127	}
	128
	129	static int pcf8563_set_datetime(struct i2c_client client, struct rtc_time tm)
	130	{
e5fc9cc0	131	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
b5a82d62 AZ	132	int i, err;
	133	unsigned char buf[9];
	134
	135	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
	136	"mday=%d, mon=%d, year=%d, wday=%d\n",
2a4e2b87	137	__func__,
b5a82d62 AZ	138	tm->tm_sec, tm->tm_min, tm->tm_hour,
	139	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	140
	141	/* hours, minutes and seconds */
fe20ba70 AB	142	buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
	143	buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
	144	buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
b5a82d62	145
fe20ba70	146	buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
b5a82d62 AZ	147
b5a82d62 AZ	148	/* month, 1 - 12 */
fe20ba70	149	buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
b5a82d62 AZ	150
b5a82d62 AZ	151	/* year and century */
fe20ba70	152	buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
cbb94502	153	if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
b5a82d62 AZ	154	buf[PCF8563_REG_MO] \|= PCF8563_MO_C;
	155
	156	buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
	157
	158	/* write register's data */
	159	for (i = 0; i < 7; i++) {
	160	unsigned char data[2] = { PCF8563_REG_SC + i,
	161	buf[PCF8563_REG_SC + i] };
	162
	163	err = i2c_master_send(client, data, sizeof(data));
	164	if (err != sizeof(data)) {
	165	dev_err(&client->dev,
	166	"%s: err=%d addr=%02x, data=%02x\n",
2a4e2b87	167	__func__, err, data[0], data[1]);
b5a82d62 AZ	168	return -EIO;
	169	}
	170	};
	171
	172	return 0;
	173	}
	174
	175	struct pcf8563_limit
	176	{
	177	unsigned char reg;
	178	unsigned char mask;
	179	unsigned char min;
	180	unsigned char max;
	181	};
	182
b5a82d62 AZ	183	static int pcf8563_rtc_read_time(struct device dev, struct rtc_time tm)
	184	{
	185	return pcf8563_get_datetime(to_i2c_client(dev), tm);
	186	}
	187
	188	static int pcf8563_rtc_set_time(struct device dev, struct rtc_time tm)
	189	{
	190	return pcf8563_set_datetime(to_i2c_client(dev), tm);
	191	}
	192
ff8371ac	193	static const struct rtc_class_ops pcf8563_rtc_ops = {
b5a82d62 AZ	194	.read_time = pcf8563_rtc_read_time,
	195	.set_time = pcf8563_rtc_set_time,
	196	};
	197
d2653e92 JD	198	static int pcf8563_probe(struct i2c_client *client,
d2653e92 JD	199	const struct i2c_device_id *id)
b5a82d62	200	{
cbb94502	201	struct pcf8563 *pcf8563;
b5a82d62 AZ	202
	203	int err = 0;
	204
e5fc9cc0	205	dev_dbg(&client->dev, "%s\n", __func__);
b5a82d62	206
e5fc9cc0 AZ	207	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
e5fc9cc0 AZ	208	return -ENODEV;
b5a82d62	209
e5fc9cc0 AZ	210	pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL);
	211	if (!pcf8563)
	212	return -ENOMEM;
b5a82d62	213
b5a82d62 AZ	214	dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
b5a82d62 AZ	215
b74d2caa AZ	216	i2c_set_clientdata(client, pcf8563);
b74d2caa AZ	217
e5fc9cc0 AZ	218	pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name,
e5fc9cc0 AZ	219	&client->dev, &pcf8563_rtc_ops, THIS_MODULE);
b5a82d62	220
e5fc9cc0 AZ	221	if (IS_ERR(pcf8563->rtc)) {
	222	err = PTR_ERR(pcf8563->rtc);
	223	goto exit_kfree;
b5a82d62 AZ	224	}
b5a82d62 AZ	225
b5a82d62 AZ	226	return 0;
b5a82d62 AZ	227
b5a82d62	228	exit_kfree:
cbb94502	229	kfree(pcf8563);
b5a82d62	230
b5a82d62 AZ	231	return err;
	232	}
	233
e5fc9cc0	234	static int pcf8563_remove(struct i2c_client *client)
b5a82d62	235	{
e5fc9cc0	236	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
b5a82d62	237
e5fc9cc0 AZ	238	if (pcf8563->rtc)
e5fc9cc0 AZ	239	rtc_device_unregister(pcf8563->rtc);
b5a82d62	240
cbb94502	241	kfree(pcf8563);
b5a82d62 AZ	242
	243	return 0;
	244	}
	245
3760f736 JD	246	static const struct i2c_device_id pcf8563_id[] = {
3760f736 JD	247	{ "pcf8563", 0 },
8ea9212c	248	{ "rtc8564", 0 },
3760f736 JD	249	{ }
	250	};
	251	MODULE_DEVICE_TABLE(i2c, pcf8563_id);
	252
e5fc9cc0 AZ	253	static struct i2c_driver pcf8563_driver = {
	254	.driver = {
	255	.name = "rtc-pcf8563",
	256	},
	257	.probe = pcf8563_probe,
	258	.remove = pcf8563_remove,
3760f736	259	.id_table = pcf8563_id,
e5fc9cc0 AZ	260	};
e5fc9cc0 AZ	261
b5a82d62 AZ	262	static int __init pcf8563_init(void)
	263	{
	264	return i2c_add_driver(&pcf8563_driver);
	265	}
	266
	267	static void __exit pcf8563_exit(void)
	268	{
	269	i2c_del_driver(&pcf8563_driver);
	270	}
	271
	272	MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
	273	MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
	274	MODULE_LICENSE("GPL");
	275	MODULE_VERSION(DRV_VERSION);
	276
	277	module_init(pcf8563_init);
	278	module_exit(pcf8563_exit);